Optimization of Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea With Ultrasound Assessment of Tongue Movement.

BACKGROUND: Hypoglossal nerve stimulation (HGNS) is an Food and Drug Administration-approved therapy for obstructive sleep apnea. Initial programming of HGNS is based on the observation of anterior tongue movement, which may not reflect opening at the retroglossal airway. We developed an ultrasonographic technique to assess the base of tongue movement with HGNS to be used to optimize the initial voltage settings. STUDY QUESTION: This study aimed to investigate the use of ultrasound to assess tongue movement with HGNS and related this measure to the apnea hypopnea index (AHI) on subsequent home sleep apnea testing or in-laboratory polysomnography with therapy. STUDY DESIGN: Seventeen subjects (n = 17) implanted with HGNS were enrolled at least 1 month postimplantation. Ultrasonographic measures were then used to optimize HGNS voltage to produce observable base of tongue protrusion without producing discomfort. Responders were defined as a reduction in AHI > 50% and an AHI of <20 events/h. RESULTS: There were 17 subjects, 11 men and 6 women, with age = 64.6 ± 9.8 years, body mass index = 27.9 ± 2.7 kg/m2, and pretreatment AHI = 36.5 ± 14.4/h, T-90% = 10.7 ± 14.8%. The mean hyoid bone excursion (HBE) in responders = 1.0 ± 0.13 cm versus 0.82 ± 0.12 cm in nonresponders (P = 0.017). HBE was correlated with AHI during HGNS treatment (coef. -0.54, P = 0.03). Best subsets regression analysis using treatment-based AHI as the dependent variable and age, body mass index, baseline AHI, HBE, and HGNS voltage as independent variables showed that HBE (coef. -44.6, P = 0.044) was the only independent predictor of response. Receiver operator curve analysis showed that HBE > 0.85 cm had a sensitivity of 83.3% and specificity of 80.0% with a positive likelihood ratio of 4.17 to predict responder status. CONCLUSION: We demonstrated that ultrasound assessment of HBE during HGNS programming is a useful tool to optimize therapy.

The PRICES statement: an ESICM expert consensus on methodology for conducting and reporting critical care echocardiography research studies.

PURPOSE: Echocardiography is a common tool for cardiac and hemodynamic assessments in critical care research. However, interpretation (and applications) of results and between-study comparisons are often difficult due to the lack of certain important details in the studies. PRICES (Preferred Reporting Items for Critical care Echocardiography Studies) is a project endorsed by the European Society of Intensive Care Medicine and conducted by the Echocardiography Working Group, aiming at producing recommendations for standardized reporting of critical care echocardiography (CCE) research studies. METHODS: The PRICE panel identified lists of clinical and echocardiographic parameters (the "items") deemed important in four main areas of CCE research: left ventricular systolic and diastolic functions, right ventricular function and fluid management. Each item was graded using a critical index (CI) that combined the relative importance of each item and the fraction of studies that did not report it, also taking experts' opinion into account. RESULTS: A list of items in each area that deemed essential for the proper interpretation and application of research results is recommended. Additional items which aid interpretation were also proposed. CONCLUSION: The PRICES recommendations reported in this document, as a checklist, represent an international consensus of experts as to which parameters and information should be included in the design of echocardiography research studies. PRICES recommendations provide guidance to scientists in the field of CCE with the objective of providing a recommended framework for reporting of CCE methodology and results.

Simulation Training for Critical Care Airway Management: Assessing Translation to Clinical Practice Using a Small Video-Recording Device.

BACKGROUND: Critical care airway management (CCAM) is a key skill for critical care physicians. Simulation-based training (SBT) may be an effective modality in training intensivists in CCAM. RESEARCH QUESTION: Is SBT of critical care fellows an effective means of providing training in CCAM, in particular in urgent endotracheal intubation? STUDY DESIGN AND METHODS: Thirteen first-year pulmonary critical care medicine (PCCM) fellows at an academic training program underwent SBT with a computerized patient simulator (CPS) in their first month of fellowship training. At the end of the training period, the fellows underwent video-based scoring using a 46-item checklist (of which 40 points could be scored) while performing a complete CCAM sequence on the CPS. They were then tested, using video-based scoring on their first real-life CCAM. Maintenance of skill at CCAM was assessed during the fellows' second and third year of training, using the same scoring method. RESULTS: For the first-year fellows, the score on the CPS was 38.3 ± 0.75 SD out of a maximum score of 40. The score on their first real-life patient CCAM was 39.0 ± 0.81 SD (P = .003 for equivalence; 95% CI for difference between real-life patient CCAM and CPS scores, 0.011-1.373). Sixteen second- and third-year fellows were tested at a real-life CCAM event later in their fellowship to examine for maintenance of skill. The mean maintenance of skill score of this group was 38.7 ± 1.14 SD. INTERPRETATION: Skill acquired through SBT of critical care fellows for CCAM transfers effectively to the real-life patient care arena. Second- and third-year fellows who had initially received SBT maintained skill at CCAM.

A Regional, Cost-Effective, Collaborative Model for Critical Care Fellows' Ultrasonography Education.

OBJECTIVE: Training in critical care ultrasonography is an essential tool in critical care medicine and recommended for fellowship programs in pulmonary and critical care medicine. Major barriers to implementing competency-based training in individual fellowship programs include a lack of expert faculty, time, and funding. Our objective was to investigate whether regional collaboration to deliver an introductory critical care ultrasonography course for fellows might overcome these barriers while achieving international training standards. METHODS: This was a retrospective review of course evaluation and learner assessment data from a 3-day ultrasonography course between 2012 and 2017. All critical care fellows (n = 545) attending the course completed pre- and postcourse surveys and postcourse knowledge and technical skills tests. Evaluation of educational outcomes was performed based on the Kirkpatrick model. RESULTS: Fellows reported minimal prior formal training in ultrasonography, and ultrasound-guided vascular access was the most common area of prior training. The course was a blended model of didactic lectures coordinated with real-time demonstration scanning using live models, hands-on training on human models and task trainers, and interpretation of ultrasonography images with a wide range of pathology. Course content included basic echocardiography and general critical care ultrasonography (lung, pleural, vascular diagnostic, vascular access, and abdominal ultrasonography). At the conclusion of the course, fellows demonstrated high levels of knowledge and skill competence on a previously validated assessment tool and significantly improved confidence in all content areas. Barriers to training at individual programs were overcome through faculty cooperation, faculty development, and cost sharing. Success of this model is supported by the sustained growth of this course. CONCLUSIONS: A regional collaborative model for training fellows in ultrasonography is a feasible, efficient, and flexible model for delivering curricula, where expertise at individual programs is not routinely available.

Assessment of Diaphragm Function and Pleural Pressures During Thoracentesis.

BACKGROUND: This prospective observational study reports on diaphragm excursion, velocity of diaphragm contraction, and changes in pleural pressure that occur with thoracentesis. METHODS: Twenty-eight patients with pleural effusion underwent therapeutic thoracentesis. Diaphragm excursion and velocity of diaphragm contraction were measured with M-mode ultrasonography of the affected hemidiaphragm. Pleural pressure was measured at each aliquot of 250 mL of fluid removal. Fluid removal was continued until no more fluid could be withdrawn, unless there was evidence of nonexpandable lung defined as a pleural elastance greater > 14.5 cm H2O/L and/or ipsilateral anterior chest discomfort. RESULTS: Twenty-three patients had expandable lung, and five patients had nonexpandable lung. Velocity of diaphragm contraction (mean ± SD) increased from 1.5 ± 0.4 cm/s to 2.8 ± 0.4 cm/s pre-thoracentesis and post-thoracentesis, respectively (CI, 0.93-1.61; P < .001) in subjects with expandable lung. Velocity of diaphragm contraction (mean ± SD) increased from 2.0 ± 0.4 cm/s to 2.3 ± 0.4 cm/s pre-thoracentesis and post-thoracentesis (P = .45) in subjects with nonexpandable lung. Diaphragm excursion was significantly increased in subjects with expandable lung at the end of thoracentesis; diaphragm excursion did not increase to a significant extent in patients with nonexpandable lung. CONCLUSIONS: The velocity of diaphragm contraction and diaphragm excursion increased in association with fluid removal with thoracentesis in patients with expandable lung, whereas it did not significantly change in patients with nonexpandable lung. This may derive from improvement in loading conditions of the diaphragm in patients with expandable lung related to its preload and length-tension characteristics.

Ultrasound Billing for Intensivists.

Point-of-care ultrasonography is a key skill for the critical care clinician and is gaining widespread acceptance by clinicians in all areas of medicine. In addition to mastery of image acquisition, image interpretation, and clinical application, intensivists need to be adept with billing for their scanning activity. This article summarizes the requirements for documentation and image storage that must be met to obtain reimbursement for point-of-care ultrasonography services.

The Rapid Assessment of Competency in Echocardiography Scale: Validation of a Tool for Point-of-Care Ultrasound.

OBJECTIVES: Increased use of point-of-care ultrasound (US) requires the development of assessment tools that measure the competency of learners. In this study, we developed and tested a tool to assess the quality of point-of-care cardiac US studies performed by novices. METHODS: In phase 1, the Rapid Assessment of Competency in Echocardiography (RACE) scale was developed on the basis of structured interviews with subject matter experts; the tool was then piloted on a small series of US studies in phase 2. In phase 3, the tool was applied to a sample of 154 point-of-care US studies performed by 12 learners; each study was independently rated by 2 experts, with quantitative analysis subsequently performed. RESULTS: Evidence of the content validity of the RACE scale was supported by a consensus exercise, wherein experts agreed on the assessment dimensions and specific items that made up the RACE scale. The tool showed good inter-rater reliability. An analysis of inter-item correlations provided support for the internal structure of the scale, and the tool was able to discriminate between learners early in their point-of-care US learning and those who were more advanced in their training. CONCLUSIONS: The RACE scale provides a straightforward means to assess learner performance with minimal requirements for evaluator training. Our results support the conclusion that the tool is an effective means of making valid judgments regarding competency in point-of-care cardiac US.

Development and Validation of an Assessment Tool for Competency in Critical Care Ultrasound.

BACKGROUND: Point-of-care ultrasound is an emerging technology in critical care medicine. Despite requirements for critical care medicine fellowship programs to demonstrate knowledge and competency in point-of-care ultrasound, tools to guide competency-based training are lacking. OBJECTIVE: We describe the development and validity arguments of a competency assessment tool for critical care ultrasound. METHODS: A modified Delphi method was used to develop behaviorally anchored checklists for 2 ultrasound applications: "Perform deep venous thrombosis study (DVT)" and "Qualify left ventricular function using parasternal long axis and parasternal short axis views (Echo)." One live rater and 1 video rater evaluated performance of 28 fellows. A second video rater evaluated a subset of 10 fellows. Validity evidence for content, response process, and internal consistency was assessed. RESULTS: An expert panel finalized checklists after 2 rounds of a modified Delphi method. The DVT checklist consisted of 13 items, including 1.00 global rating step (GRS). The Echo checklist consisted of 14 items, and included 1.00 GRS for each of 2 views. Interrater reliability evaluated with a Cohen kappa between the live and video rater was 1.00 for the DVT GRS, 0.44 for the PSLA GRS, and 0.58 for the PSSA GRS. Cronbach α was 0.85 for DVT and 0.92 for Echo. CONCLUSIONS: The findings offer preliminary evidence for the validity of competency assessment tools for 2 applications of critical care ultrasound and data on live versus video raters.

The effect of point-of-care ultrasonography on imaging studies in the medical ICU: a comparative study.

BACKGROUND: Point-of-care ultrasonography performed by frontline intensivists offers the possibility of reducing the use of traditional imaging in the medical ICU (MICU). We compared the use of traditional radiographic studies between two MICUs: one where point-of-care ultrasonography is used as a primary imaging modality, the other where it is used only for procedure guidance. METHODS: This study was a retrospective 3-month chart review comparing the use of chest radiographs, CT scans (chest and abdomen/pelvis), transthoracic echocardiography performed by the cardiology service, and DVT ultrasonography studies performed by the radiology service between two MICUs of similar size and acuity and staffing levels. RESULTS: Total number of admissions, patient demographics, and disease acuity were similar between MICUs. Comparing the non-point-of-care ultrasonography MICU with the point-of-care ultrasonography MICU, there were 3.75 ± 4.6 vs 0.82 ± 1.85 (P < .0001) chest radiographs per patient, 0.10 ± 0.31 vs 0.04 ± 0.20 (P = .0007) chest CT scans per patient, 0.17 ± 0.44 vs 0.05 ± 0.24 (P < .0001) abdomen/pelvis CT scans per patient, 0.20 ± 0.47 vs 0.02 ± 0.14 (P < .0001) radiology service-performed DVT studies per patient, and 0.18 ± 0.40 vs 0.07 ± 0.26 (P < .0001) cardiology service-performed transthoracic echocardiography studies per patient, respectively. CONCLUSIONS: The use of point-of-care ultrasonography in an MICU is associated with a significant reduction in the number of imaging studies performed by the radiology and cardiology services.

Ultrasound assessment of pulmonary embolism in patients receiving CT pulmonary angiography.

BACKGROUND: CT pulmonary angiography (CTPA) is considered the gold standard for the diagnosis of pulmonary embolism (PE) and is frequently performed in patients with cardiopulmonary complaints. However, indiscriminate use of CTPA results in significant exposure to ionizing radiation and contrast. We studied the accuracy of a bedside ultrasound protocol to predict the need for CTPA. METHODS: This was an observational study performed by pulmonary/critical care physicians trained in critical care ultrasonography. Screening ultrasonography was performed when a CTPA was ordered to rule out PE. The ultrasound examination consisted of a limited ECG, thoracic ultrasonography, and lower extremity deep venous compression study. We predicted that CTPA would not be needed if either DVT was found or clear evidence of an alternative diagnosis was established. CTPA parenchymal and pleural findings, and, when available, formal DVT and ECG results, were compared with our screening ultrasound findings. RESULTS: Of 96 subjects who underwent CTPA, 12 subjects (12.5%) were positive for PE. All 96 subjects had an ultrasound study; two subjects (2.1%) were positive for lower extremity DVT, and 54 subjects (56.2%) had an alternative diagnosis suggested by ultrasonography, such as alveolar consolidation consistent with pneumonia or pulmonary edema, which correlated with CTPA findings. In no patient did the CTPA add an additional diagnosis over the screening ultrasound study. CONCLUSIONS: We conclude that ultrasound examination indicated that CTPA was not needed in 56 of 96 patients (58.3%). A screening, point-of-care ultrasonography protocol may predict the need for CTPA. Furthermore, an alternative diagnosis can be established that correlates with CTPA. This study needs further verification, but it offers a possible approach to reduce the cost and radiation exposure that is associated with CTPA.

Thoracic ultrasonography for the pulmonary specialist.

Thoracic ultrasonography is a noninvasive and readily available imaging modality that has important applications in pulmonary medicine outside of the ICU. It allows the clinician to diagnose a variety of thoracic disorders at the point of care. Ultrasonography is useful in imaging lung consolidation, pleural-based masses and effusions, pneumothorax, and diaphragmatic dysfunction. It can identify complex or loculated effusions and be useful in planning treatment. Identifying intrathoracic mass lesions can guide sampling by aspiration and biopsy. This article summarizes thoracic ultrasonography applications for the pulmonary specialist, related procedural codes, and reimbursement. The major concepts are illustrated with cases. These case summaries are enhanced with online supplemental videos and chest radiograph, chest CT scan, and ultrasound correlation.

A rapid, safe, and low-cost technique for the induction of mild therapeutic hypothermia in post-cardiac arrest patients.

AIM OF STUDY: The benefits of inducing mild therapeutic hypothermia (MTH) in cardiac arrest patients are well established. Timing and speed of induction have been related to improved outcomes in several animal trials and one human study. We report the results of an easily implemented, rapid, safe, and low-cost protocol for the induction of MTH. METHODS: All in-hospital cardiac arrest (IHCA) and out-of-hospital cardiac arrest (OHCA) patients admitted to an intensive care unit meeting inclusion criteria were cooled using a combination modality of rapid, cold saline infusion (CSI), evaporative surface cooling, and ice water gastric lavage. Cooling tasks were performed with a primary emphasis on speed. The main endpoints were the time intervals between return of spontaneous circulation (ROSC), initiation of hypothermia (IH), and achievement of target temperature (TT). RESULTS: 65 patients underwent MTH during a 3-year period. All patients reached target temperature. Median ROSC-TT was 134min. Median ROSC-IH was 68min. Median IH-TT was 60min. IH-TT cooling rate was 2.6°C/h. Complications were similar to that of other large trials. 31% of this mixed population of IHCA and OHCA patients recovered to a Pittsburgh cerebral performance score (CPC) of 1 or 2. CONCLUSION: A protocol using a combination of core and surface cooling modalities was rapid, safe, and low cost in achieving MTH. The cooling rate of 2.6°C/h was superior to most published protocols. This method uses readily available equipment and reduces the need for costly commercial devices.

Gender disparity in failure rate for arterial catheter attempts.

We examined risk factors associated with failure of arterial catheterization in the medical intensive care unit of a large urban teaching hospital. We analyzed 92 consecutive arterial catheterizations by internal medicine house staff and critical care fellows. Of the 92 attempts, 26.1% were done on femoral arteries, and 73.9% were done on radial arteries. Failure, which occurred in 28% of attempts, was more common in female patients (P < .001). The failure rate was 50.0% for attempts on femoral arteries and 20.6% on radial arteries. Systolic blood pressure was significantly lower in patients where the attempt failed (P = .024). In univariate analyses, hemoglobin values were lower (P = .028) and number of percutaneous punctures were higher (P = .019) in patients where catheterization failed. After multivariate analysis, only gender and systolic blood pressure remained statistically significant. The strongest predictor of failure was female gender. A possible explanation not explored here could be smaller arterial size in female patients.